The analysis of blood flow perfusion (Perfusion) is very effective for the functional diagnosis of organs. Perfusion analysis includes approximately identifying the transfer coefficient between a time density curve (TDC) associated with an artery inflowing into an organ and a time density curve associated with an organ tissue by, for example, the least squares method and calculating a perfusion index from the identified transfer coefficient.
For example, unlike perfusion analysis on the brain, analysis on feading and functional blood vessels of abdominal organs is performed by using various kinds of combinations of kinetic models and analysis models selected from a plurality of types of kinetic models (compartment models) and a plurality of types of analysis models in accordance with target organs, because feading and functional blood vessels vary for each organ.
Therefore, a kinetic index exhibits low suitability in a region other than an organ region corresponding to a selected kinetic model and analysis model. Although it is necessary to exclude such a region from perfusion diagnosis, it is not possible to clearly recognize the region. In general, since a tissue in an abdominal region is an assembly of soft tissues exhibiting small CT value differences, the suitability of even an organ region segmented from a CT image is not high.